Method of gaming, a gaming system and a game controller

ABSTRACT

A method of gaming comprising conducting a series of game rounds in response to determining that the series should commence, at least one first game round of the series of game rounds being conducted by controlling a display to display a first number of special symbols at a corresponding first number of display positions of a set of display positions, selecting symbols for the remaining display positions from a selection set of symbols, and determining a game round outcome from the displayed symbols, and at least one second game round of the series of game rounds being conducted by controlling a display to display a second number of special symbols greater than the first number at a corresponding second number of display positions of a set of display positions, selecting symbols for the remaining display positions from a selection set of symbols, and determining a game round outcome from the displayed symbols.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of priority to Australian Provisional Patent Application No. 2008902584, filed on May 23, 2008, entitled “A METHOD OF GAMING, A GAMING SYSTEM AND A GAME CONTROLLER”, which is herein incorporated by reference in its entirety.

FIELD

The present invention relates to a method of gaming, a gaming system and a game controller.

BACKGROUND TO THE INVENTION

Gaming systems are known comprising a game controller arranged to randomly display several symbols from a predetermined set of symbols and to determine a game outcome such as a game win based on the displayed symbols. Such gaming systems may commonly be implemented as a video machine with selected symbols are displayed in virtual display positions corresponding for example to spinning reels, on a video display.

There is a need for alternative gaming systems to add to player excitement and enjoyment.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a method of gaming including conducting a series of game rounds in response to determining that the series should commence,

-   -   at least one first game round of the series of game rounds being         conducted by controlling a display to display a first number of         special symbols at a corresponding first number of display         positions of a set of display positions, selecting symbols for         the remaining display positions from a first selection set of         symbols, and determining a game round outcome from the displayed         symbols, and     -   at least one second game round of the series of game rounds         being conducted by controlling a display to a second number of         special symbols at a corresponding second number of display         positions of a set of display positions where the second number         is greater than the first number, selecting symbols for the         remaining display positions from a second selection set of         symbols, and determining a game round outcome from the displayed         symbols.

In an embodiment, the at least one second game round commences after a designated number of first game rounds.

In an embodiment, each selection set of symbols represents symbols positioned on a plurality of spinnable reels, and the display positions represent visible reel positions after a spin of the reels.

In an embodiment, the first and second special symbols are wild symbols.

In an embodiment, the first number of first special symbols is one and the second number of second special symbols is two.

In an embodiment, the first special symbols are positioned to correspond to one reel and shift between reels in subsequent game rounds in the series.

In an embodiment, the first special symbols shift in one direction by one reel position after each game round and the designated number of first game rounds is equal to the number of reels.

In an embodiment, the method of gaming further includes conducting at least one third game round by controlling a display to display a third number of special symbols at a corresponding third number of display positions of a set of display positions, selecting symbols for the remaining display positions from a selection set of symbols, and determining a game round outcome from the displayed symbols.

In an embodiment, the third number is greater than the second number.

In an embodiment, the method includes initiating the series of game rounds as a series of free game rounds in response to a trigger event occurring in a base game round during which symbols are selected from the same selection symbol set but outcomes are determined in a different manner.

According to a second aspect of the invention there is provided a game controller for a gaming system, the game controller arranged to:

-   -   conduct a series of game rounds in response to determining that         the series should commence,     -   at least one first game round of the series of game rounds being         conducted by controlling a display to display a first number of         special symbols at a corresponding first number of display         positions of a set of display positions, selecting symbols for         the remaining display positions from a first selection set of         symbols, and determining a game round outcome from the displayed         symbols, and     -   at least one second game round of the series of game rounds         being conducted by controlling a display to display a second         number of special symbols at a corresponding second number of         display positions of a set of display positions where the second         number is greater than the first number, selecting symbols for         the remaining display positions from a second selection set of         symbols, and determining a game round outcome from the displayed         symbols.

In an embodiment, the game controller includes a symbol selector for selecting symbols for display in the display positions.

In an embodiment, the game controller includes a special symbol controller for controlling the number and display positions of the special symbols.

In an embodiment, the special symbol controller is arranged to determine the display position at least partially on a random basis.

In an embodiment, the game controller includes an outcome determiner for determining each game round outcome.

In an embodiment, the game controller includes a feature game initiator arranged to initiate the series of game rounds as a series of free game rounds in response to a trigger event occurring in a base game round.

In an embodiment, the game controller is implemented, at least in part, by a processor executing code stored in a memory.

In an embodiment, the game controller controls commencement of the at least one second game round to occur after a designated number of first game rounds.

In an embodiment, each selection set of symbols represents symbols positioned on a plurality of spinnable reels, and the display positions represent visible reel positions after a spin of the reels.

In an embodiment, the first and second special symbols are wild symbols.

In an embodiment, the first number of first special symbols is one and the second number of second special symbols is two.

In an embodiment, the first special symbols are positioned to correspond to one reel and shift between reels in subsequent game rounds in the series.

In an embodiment, the first special symbols shift in one direction by one reel position after each game round and the designated number of first game rounds is equal to the number of reels.

In an embodiment, the game controller is further arranged to conducting at least one third game round by controlling a display to display a third number of special symbols at a corresponding third number of display positions of a set of display positions, selecting symbols for the remaining display positions from a third selection set of symbols, and determining a game round outcome from the displayed symbols.

In an embodiment, the third number is greater than the second number.

According to a third aspect of the invention there is provided a gaming system including

-   -   a display for symbols to be displayed at a set of display         positions to a player; and

a game controller arranged to:

conduct a series of game rounds in response to determining that the series should commence,

-   -   at least one first game round of the series of game rounds being         conducted by controlling a display to display a first number of         special symbols at a corresponding first number of display         positions of a set of display positions, selecting symbols for         the remaining display positions from a first selection set of         symbols, and determining a game round outcome from the displayed         symbols, and     -   at least one second game round of the series of game rounds         being conducted by controlling a display to display a second         number of special symbols at a corresponding second number of         display positions of a set of display positions where the second         number is greater than the first number, selecting symbols for         the remaining display positions from a second selection set of         symbols, and determining a game round outcome from the displayed         symbols.

In an embodiment, the display forms part of a player interface further including a game play mechanism operable by the player to play the game.

In an embodiment, the game controller includes a symbol selector for selecting symbols for display in the display positions.

In an embodiment, the game controller includes a special symbol controller for controlling the number and display positions of the special symbols.

In an embodiment, the special symbol controller is arranged to determine the display position at least partially on a random basis.

In an embodiment, the game controller includes an outcome determiner for determining each game round outcome.

In an embodiment, the game controller includes a feature game initiator arranged to initiate the series of game rounds as a series of free game rounds in response to a trigger event occurring in a base game round.

In an embodiment, the game controller is implemented, at least in part, by a processor executing code stored in a memory.

In an embodiment, the game controller controls commencement of the at least one second game round to occur after a designated number of first game rounds.

In an embodiment, each selection set of symbols represents symbols positioned on a plurality of spinnable reels, and the display positions represent visible reel positions after a spin of the reels.

In an embodiment, the first and second special symbols are wild symbols.

In an embodiment, the first number of first special symbols is one and the second number of second special symbols is two.

In an embodiment, the first special symbols are positioned to correspond to one reel and shift between reels in subsequent game rounds in the series.

In an embodiment, the first special symbols shift in one direction by one reel position after each game round and the designated number of first game rounds is equal to the number of reels.

In an embodiment, the game controller is further arranged to conducting at least one third game round by controlling a display to display a third number of special symbols at a corresponding third number of display positions of a set of display positions, selecting symbols for the remaining display positions from a third selection set of symbols, and determining a game round outcome from the displayed symbols.

In an embodiment, the third number is greater than the second number.

In a fourth aspect, the invention provides a gaming system including:

-   -   means for conducting a series of game rounds in response to         determining that the series should commence,     -   means for controlling a display to display a first number of         special symbols at a corresponding first number of display         positions of a set of display positions in at least one first         game round of the series of game rounds, means for selecting         symbols for the remaining display positions from a first         selection set of symbols, and means for determining a game round         outcome from the displayed symbols, and     -   means for controlling a display to display a second number of         special symbols at a corresponding second number of display         positions of a set of display positions where the second number         is greater than the first number in at least one second game         round of the series of game rounds, means for selecting symbols         for the remaining display positions from a second selection set         of symbols, and means for determining a game round outcome from         the displayed symbols.

In a fifth aspect, the invention provides a gaming machine including:

-   -   a display mounted within a cabinet for symbols to be displayed         at a set of display positions to a player,     -   an input device operable by a player to initiate a play of a         game,     -   a game controller disposed in the cabinet in data communication         with the display and the input device and including a processor         and a memory storing game program code which when executed in         response to the initiation of play, causes the game controller         to conduct a series of game rounds in response to determining         that the series should commence,     -   at least one first game round of the series of game rounds being         conducted by controlling a display to display a first number of         special symbols at a corresponding first number of display         positions of a set of display positions, selecting symbols for         the remaining display positions from a first selection set of         symbols, and determining a game round outcome from the displayed         symbols, and     -   at least one second game round of the series of game rounds         being conducted by controlling a display to display a second         number of special symbols at a corresponding second number of         display positions of a set of display positions where the second         number is greater than the first number, selecting symbols for         the remaining display positions from a second selection set of         symbols, and determining a game round outcome from the displayed         symbols.

According to a sixth aspect of the invention there is provided computer program code when executed by a computer causes the computer to implement any of the embodiments of the method of gaming of the first aspect of the invention.

According to a seventh aspect of the invention there is provided a computer readable medium including the program code of the fourth aspect of the invention.

According to an eighth aspect of the invention there is provided a data signal including the computer program code of the fourth aspect of the invention.

According to a ninth aspect of the invention there is provided transmitting or receiving the program code of the first aspect.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the invention are described by way of example in conjunction with the following drawings, in which:

FIG. 1 is a block diagram of the core components of a gaming system.

FIG. 2 is a perspective view of a stand alone single player gaming machine;

FIG. 3 is a block diagram of the functional components of a gaming machine;

FIG. 4 is a schematic diagram of the functional components of a memory;

FIG. 5 is a schematic diagram of a network gaming system;

FIG. 6 is a further block diagram of a multiplayer gaming system; and

FIG. 7 shows a flow diagram for a method of an embodiment of the invention.

FIG. 8 shows an exemplary display of visible reels positions.

Features, further aspects, and advantages of the present invention will become apparent from the following description of embodiments thereof, by way of example only, with reference to the accompanying drawings. Also, various embodiments of the aspects described in the preceding paragraphs will be apparent from the appended claims, the following description and/or the accompanying drawings. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings.

DETAILED DESCRIPTION

Although the following discloses example methods, systems, articles of manufacture, and apparatus including, among other components, software executed on hardware, it should be noted that such methods and apparatus are merely illustrative and should not be considered as limiting. For example, it is contemplated that any or all of these hardware and software components could be embodied exclusively in hardware, exclusively in software, exclusively in firmware, or in any combination of hardware, software, and/or firmware. Accordingly, while the following describes example methods, systems, articles of manufacture, and apparatus, the examples provided are not the only way to implement such methods, systems, articles of manufacture, and apparatus.

When any of the appended claims are read to cover a purely software and/or firmware implementation, at least one of the elements is hereby expressly defined to include a tangible medium such as a memory, DVD, CD, etc. storing the software and/or firmware.

Referring to the drawings, there is shown a gaming system having a game controller arranged to implement a game having a series of game rounds wherein special symbols, such as wild symbols, are controlled such that they are displayed at one or more display positions and the number of special symbols increases during the series of game rounds. In an embodiment, the special symbols move from reel to reel.

The gaming system may take a number of different forms. In a first form of the single player component of the invention, a stand alone gaming machine is provided wherein all or most components for implementing the game are present in a player operable gaming machine.

In a second form, a distributed architecture is provided wherein some of the components for implementing the game are present in a player operable gaming machine and some of the components for implementing the game are located remotely relative to the gaming machine. For example, a “thick client” architecture may be used wherein part of the game is executed on a player operable gaming machine and part of the game is executed remotely, such as by a gaming server; or a “thin client” architecture may be used wherein most of the game is executed remotely such as by a gaming server and a player operable gaming machine is used only to display audible and/or visible gaming information to the player and receive gaming inputs from the player.

However, it will be understood that other arrangements are envisaged. For example, an architecture may be provided wherein a gaming machine is networked to a gaming server and the respective functions of the gaming machine and the gaming server are selectively modifiable. For example, the gaming system may operate in stand alone gaming machine mode, “thick client” mode or “thin client” mode depending on the game being played, operating conditions, and so on. Other variations will be apparent to persons skilled in the art.

Irrespective of the form, the gaming system includes several core components. At the broadest level, the core components are a player interface 50 and a game controller 60 as illustrated in FIG. 1. The player interface is arranged to enable manual interaction between a player and the gaming system and for this purpose includes the input/output components for the player to enter instructions and play the game.

Components of the player interface may vary from embodiment to embodiment but will typically include a credit mechanism 52 to enable a player to input credits and receive payouts, one or more displays 54, a game play mechanism 56 including one or more input devices that enable a player to input game play instructions (e.g. to place bets), and one or more speakers 58.

The game controller 60 is in data communication with the player interface and typically includes a processor 62 that processes the game play instructions in accordance with game play rules and outputs game play outcomes to the display. Typically, the game play instructions are stored as program code in a memory 64 but can also be hardwired. Herein the term “processor” is used to refer generically to any device that can process game play instructions in accordance with game play rules and may include: a microprocessor, microcontroller, programmable logic device or other computational device, a general purpose computer (e.g. a PC) or a server.

A gaming system in the form of a stand alone gaming machine 10 is illustrated in FIG. 2. The gaming machine 10 includes a console 12 having a display 14 on which are displayed representations of a game 16 that can be played by a player. A mid-trim 20 of the gaming machine 10 houses a bank of buttons 22 for enabling a player to interact with the gaming machine, in particular during game play. The mid-trim 20 also houses a credit input mechanism 24 which in this example includes a coin input chute 24A and a bill collector 24B. Other credit input mechanisms may also be employed, for example, a card reader for reading a smart card, debit card or credit card. A player marketing module (not shown) having a reading device may also be provided for the purpose of reading a player tracking device, for example as part of a loyalty program. The player tracking device may be in the form of a card, flash drive or any other portable storage medium capable of being read by the reading device.

A top box 26 may carry artwork 28, including for example pay tables and details of bonus awards and other information or images relating to the game. Further artwork and/or information may be provided on a front panel 29 of the console 12. A coin tray 30 is mounted beneath the front panel 29 for dispensing cash payouts from the gaming machine 10.

The display 14 shown in FIG. 2 is in the form of a video display unit, particularly a cathode ray tube screen device. Alternatively, the display 14 may be a liquid crystal display, plasma screen, any other suitable video display unit, or the visible portion of an electromechanical device. The top box 26 may also include a display, for example a video display unit, which may be of the same type as the display 14, or of a different type.

FIG. 3 shows a block diagram of operative components of a typical gaming machine which may be the same as or different to the gaming machine of FIG. 2.

The gaming machine 100 includes a game controller 101 having a processor 102. Instructions and data to control operation of the processor 102 are stored in a memory 103, which is in data communication with the processor 102. Typically, the gaming machine 100 will include both volatile and non-volatile memory and more than one of each type of memory, with such memories being collectively represented by the memory 103.

The gaming machine has hardware meters 104 for purposes including ensuring regulatory compliance and monitoring player credit, an input/output (I/O) interface 105 for communicating with peripheral devices of the gaming machine 100. The input/output interface 105 and/or the peripheral devices may be intelligent devices with their own memory for storing associated instructions and data for use with the input/output interface or the peripheral devices. A random number generator module 113 generates random numbers for use by the processor 102. Persons skilled in the art will appreciate that the reference to random numbers includes pseudo-random numbers.

In the example shown in FIG. 3, a player interface 120 includes peripheral devices that communicate with the game controller 101 include one or more displays 106, a touch screen and/or buttons 107, a card and/or ticket reader 108, a printer 109, a bill acceptor and/or coin input mechanism 110 and a coin output mechanism 111. Additional hardware may be included as part of the gaming machine 100, or hardware may be omitted based on the specific implementation. For example, while buttons or touch screens are typically used in gaming machines to allow a player to place a wager and initiate a play of a game any input device that enables the player to input game play instructions may be used. For example, in some gaming machines a mechanical handle is used to initiate a play of the game.

In addition, the gaming machine 100 may include a communications interface, for example a network card 112. The network card may, for example, send status information, accounting information or other information to a central controller, server or database and receive data or commands from the central controller, server or database.

FIG. 4 shows a block diagram of the main components of an exemplary memory 103. The memory 103 includes RAM 103A, EPROM 103B and a mass storage device 103C. The RAM 103A typically temporarily holds program files for execution by the processor 102 and related data. The EPROM 103B may be a boot ROM device and/or may contain some system or game related code. The mass storage device 103C is typically used to store game programs, the integrity of which may be verified and/or authenticated by the processor 102 using protected code from the EPROM 103B or elsewhere.

It is also possible for the operative components of the gaming machine 100 to be distributed, for example input/output devices 106,107,108,109,110,111 to be provided remotely from the game controller 101.

FIG. 5 shows a gaming system 200 in accordance with an alternative embodiment. The gaming system 200 includes a network 201, which for example may be an Ethernet network. Gaming machines 202, shown arranged in three banks 203 of two gaming machines 202 in FIG. 5, are connected to the network 201. The gaming machines 202 provide a player operable interface and may be the same as the gaming machines 10,100 shown in FIGS. 2 and 3, or may have simplified functionality depending on the rules, guidelines, preferences, and/or requirements for implementing game play. While banks 203 of two gaming machines are illustrated in FIG. 5, banks of one, three or more gaming machines are also envisaged.

One or more displays 204 may also be connected to the network 201. For example, the displays 204 may be associated with one or more banks 203 of gaming machines. The displays 204 may be used to display representations associated with game play on the gaming machines 202, and/or used to display other representations, for example promotional or informational material.

In a thick client embodiment, game server 205 implements part of the game played by a player using a gaming machine 202 and the gaming machine 202 implements part of the game. With this embodiment, as both the game server and the gaming device implement part of the game, they collectively provide a game controller. A database management server 206 may manage storage of game programs and associated data for downloading or access by the gaming devices 202 in a database 206A. Typically, if the gaming system enables players to participate in a Jackpot game, a Jackpot server 207 will be provided to perform accounting functions for the Jackpot game. A loyalty program server 212 may also be provided.

In a thin client embodiment, game server 205 implements most or all of the game played by a player using a gaming machine 202 and the gaming machine 202 essentially provides only the player interface. With this embodiment, the game server 205 provides the game controller. The gaming machine will receive player instructions, pass these to the game server which will process them and return game play outcomes to the gaming machine for display. In a thin client embodiment, the gaming machines could be computer terminals, e.g. PCs running software that provides a player interface operable using standard computer input and output components. Other client/server configurations are possible, and further details of a client/server architecture can be found in WO 2006/052213 and PCT/SE2006/000559, the disclosures of which are incorporated herein by reference.

Servers are also typically provided to assist in the administration of the gaming network 200, including for example a gaming floor management server 208, and a licensing server 209 to monitor the use of licenses relating to particular games. An administrator terminal 210 is provided to allow an administrator to run the network 201 and the devices connected to the network.

The gaming system 200 may communicate with other gaming systems, other local networks, for example a corporate network, and/or a wide area network such as the Internet, for example through a firewall 211.

Persons skilled in the art will appreciate that in accordance with known techniques, functionality at the server side of the network may be distributed over a plurality of different computers. For example, elements may be run as a single “engine” on one server or a separate server may be provided. For example, the game server 205 could run a random generator engine. Alternatively, a separate random number generator server could be provided. Further, persons skilled in the art will appreciate that a plurality of games servers could be provided to run different games or a single game server may run a plurality of different games based on the terminals.

Further Detail of Exemplar Gaming System

The player operates the game play mechanism 56 to initiate a play of the gaming system. The player's operation of the game play mechanism specifies, in part, what will be evaluated when the play is conducted and thereby what the player is entitled to win from the game. Persons skilled in the art will appreciate that a player's win entitlement will vary from game to game dependent on player selections. In most spinning reel games, it is typical for the player's entitlement to be affected by the amount they wager and selections they make (i.e. the nature of the wager). For example, a player's win entitlement may be based on how many lines they will play in each game—i.e. a minimum of one line up to the maximum number of lines allowed by the game (noting that not all permutations of win lines may be available for selection. Such win lines are typically formed by a combination of displayed symbol positions, one from each reel, the symbol positions being located relative to one another such that they form a line.

In many games, the player's win entitlement is not strictly limited to the lines they have selected, for example, “scatter” pays are awarded independently of a player's selection of pay lines and are an inherent part of the win entitlement.

Persons skilled in the art, will appreciate that in other embodiments, the player may obtain a win entitlement by selecting a number of reels to play. Such games are marketed under the trade name “Reel Power” by Aristocrat Leisure Industries Pty Ltd. The selection of the reel means that each symbol of the reel can be substituted for a symbol at one or more designated display positions. In other words, all symbol positions of a selected reel can be used to form symbol combinations with designated, displayed symbol positions of other reels.

In other embodiments a player win entitlement may be affected by purchasing access to particular pay tables—e.g. a first bet amount entitles the player to wins including cherries and a second amount entitles them to wins including plums.

The game controller of the preferred embodiment is shown in more detail in FIG. 6. Game controller 60 incorporates a symbol selector 610 that selects symbols a set of symbols (a display set) 643 from symbol selection set 642 using random numbers from random number generator 650, to appear on the display 54 in a base game. In one example, the symbol set corresponds to reels having a defined order and symbol selector determines the stop position using the random number generator. For example, if there are five reels, each having twenty symbols, the stop determining function might determine that the stop positions are positions: 3, 13, 7, 9 and 17. The spinning of the reels is then controlled so that each symbol comes to a stop in the same row, typically a predetermined row of a plurality of rows of symbols. When a reels stops, the symbols will be in one of a plurality of possible symbol positions for that reel relative to the stop position. Often, particular stop positions are weighted so as to control the probability of certain outcomes. Outcome determiner 630 determines whether the selected symbols (stored as symbol display set 643) correspond to a winning outcome and updates meter data 646 as appropriate.

In addition to the above, feature game round controller 625 is arranged to monitor for a trigger event which may be any of the known triggers in the art, including a particular symbol combination, a number of games played or an amount wagered in a time period. In another embodiment, feature game round controller 625 is operably connected with random number generator 650 to randomly determine whether a feature game round should be initiated. Feature game round controller in 625 includes a special symbol controller adapted to control the number and display position of special symbols from special symbol set 641 during a series of game rounds conducted feature game round controller 620. While, the special symbol controller 620 controls the number of special symbols and their display positions, the remaining display positions of the set of display positions are filled by selecting them in the same manner as the base game, so that the special symbols under control of the special symbol controller effectively overwrite the selected symbols at the position where they are place by the special symbol controller 620.

Outcome determiner 630 determines an outcome for the game round based on the symbols in symbol display set 643 which is formed from the controlled symbols and the selected symbols, and updates meter data 646 using any prize data 645 in each game round.

Persons skilled in the art will appreciate that one or more of these components could be provided in other ways, for example by a dedicated circuit.

The special symbol controller 620 is arranged to increase the number of special symbols at least once during the series of game rounds, typically after a predetermined number of game rounds. Thus, at least one first game round involves a first number of special symbols and at least one second game round involves a second, larger number of special symbols. The number of special symbols may be varied again during the game rounds either by being increased or decreased. In an embodiment, the special symbol controller 620 also controls the position of the special symbols in each game round so that they move in a desired way.

As described above, the outcome determiner determines whether to award any prizes after each game round. These are initially accrued on a win meter of meter data 646. At the conclusion of the series of game rounds (“free games”), the accrued amount is transferred to a credit meter of credit data. In some embodiments, the player may be offered the chance to gamble the amount on the win meter prior to it being transferred to the credit meter.

As indicated above, the special symbol may be a wild symbol but may also be some other symbol which has a particular effect on the game such as a multiplier or a symbol which forms part of a trigger combination for triggering a further feature or retriggering the series of game rounds.

In the above embodiment, the symbols other than the selected symbols, are selected from the same symbol set in the first and second game rounds, however, persons skilled in the art will appreciate that they could be selected from different sets of symbols. Put another way, symbols could be selected from a first set of symbols in first game rounds and a second set in second game rounds, and the first and second sets could be the same or different. In one embodiment, there can be a third set of game rounds (or more than three sets of game rounds) where there are more special symbols than the second round and symbols can be selected from a third set.

The method 700 of an embodiment is described with reference to FIG. 7. Play is started by the player and a base game commences 705 during which symbol selector 610 selects the symbol display set 643 using random numbers from random number generator 650 and the display set appears in the display positions on display 54. In a spinning reel game, this corresponds to the visible reel positions after the spin of the reels. It is determined 710 whether a series of game rounds is triggered. If it is triggered, a counter is initialised 715, specifying that this is the first game round. It is determined 720 whether a first designated number of game rounds N has been played. If not, the display 54 is controlled to display a first number of special symbols and the remaining symbols are selected 730 before an outcome is determined 740. The counter is then increased 745.

When the number of game rounds G is greater than a designated number N of game rounds at least one additional special symbol is added as described in further detail below. At step 750 it is determined whether a second number of game rounds M has been played, where M is greater than N and in this embodiment specifies the total number of game rounds to be played. If G is less than or equal to M, the method proceeds by controlling 755 the display 54 to display a second number of special symbols greater than the first number of special symbols, selecting the remaining symbols 730 and determining the game round outcome. The counter is increased 745 and second game rounds with the second number of special symbols continue until G is greater than M and the series of game rounds ends 760.

EXAMPLE 1

A detailed example of an embodiment of the invention will now be described. As shown in FIG. 8, the display positions of a game of five spinning reels 820 a to 820 e is shown, with three visible reel positions per reel. Non-feature game rounds involve determination of a game round outcome on the basis of combinations of the symbols (such as shown in FIG. 8) along win lines played by the player, which may be the centre line in a simple example.

On the trigger, which may be random or on the basis of a symbol or combination of symbols in the display positions, the series of feature games is initiated. In this example, whatever win lines were being evaluated in the base game are evaluated in each game round of the series of game rounds. In this example, there are ten game rounds in the series and the first five game rounds are played with one special symbol before the number of special symbols is increased to two. In this example the special symbol is a WILD symbol which can substitute for all other symbols to form winning combinations.

In this example, in the first game round one WILD symbol is placed at a random display position of the three reels corresponding to reel 5. In this embodiment, the WILD symbol covers and overwrites the symbol which would otherwise occupy that display position. A game round spin then occurs to select the remaining symbols which are evaluated together with the WILD symbol. The timing of the placement of the WILD symbol may be controlled to suit the game but in one embodiment is placed while the reels spin to add to anticipation.

The WILD on reel 5 then disappears. In free game 2, one WILD is randomly placed on top of a certain position on reel 4 and an outcome is determined.

The WILD on reel 4 disappears. In free game 3, one WILD is randomly placed on top of a certain position on reel 3 and an outcome is determined.

The WILD on reel 3 disappears. In free game 4, one WILD is randomly placed on top of a certain position on reel 2 and an outcome is determined.

The WILD on reel 2 disappears. In free game 5, one WILD is randomly placed on top of a certain position on reel 1 and an outcome is determined.

The WILD on reel 1 disappears. In free game 6, two WILD are randomly placed on top of a certain position on reel 1 and an outcome is determined.

The WILD on reel 1 disappears. In free game 7, two WILD is randomly placed on top of a certain position on reel 2 and an outcome is determined.

The WILD on reel 2 disappears. In free game 8, two WILD is randomly placed on top of a certain position on reel 3 and an outcome is determined.

The WILD on reel 3 disappears. In free game 9, two WILD is randomly placed on top of a certain position on reel 4 and an outcome is determined.

The WILD on reel 4 disappears. In free game 10, two WILD is randomly placed on top of a certain position on reel 5, an outcome is determined, and the series of free games ends.

Persons skilled in the art will appreciate that the method of the embodiment could be embodied in program code. The program code could be supplied in a number of ways, for example on a computer readable medium, such as a disc or a memory (for example, that could replace part of memory 103) or as a data signal (for example, by downloading it from a server).

Persons skilled in the art will also appreciate that many variations may be made to the invention without departing from the scope of the invention. In particular that features described above could be combined to form alternative embodiments.

In the claims which follow and in the preceding description of the invention, except where the context indicates otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. Several embodiments are described above with reference to the drawings. These drawings illustrate certain details of specific embodiments that implement the systems and methods and programs of the present invention. However, describing the invention with drawings should not be construed as imposing on the invention any limitations associated with features shown in the drawings. It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

The present invention contemplates methods, systems and program products on any electronic device and/or machine-readable media suitable for accomplishing its operations. Certain embodiments of the present invention may be implemented using an existing computer processor and/or by a special purpose computer processor incorporated for this or another purpose or by a hardwired system, for example.

Embodiments within the scope of the present invention include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media may comprise RAM, ROM, PROM, EPROM, EEPROM, Flash, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such a connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions comprise, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions. 

1. A method of gaming comprising conducting a series of game rounds in response to determining that the series should commence, at least one first game round of the series of game rounds being conducted by controlling a display to display a first number of special symbols at a corresponding first number of display positions of a set of display positions, selecting symbols for the remaining display positions from a first selection set of symbols, and determining a game round outcome from the displayed symbols, and at least one second game round of the series of game rounds being conducted by controlling a display to display a second number of special symbols at a corresponding second number of display positions of a set of display positions where the second number is greater than the first number, selecting symbols for the remaining display positions from a second selection set of symbols, and determining a game round outcome from the displayed symbols.
 2. A method of gaming as claimed in claim 1, wherein the at least one second game round commences after a designated number of first game rounds.
 3. A method of gaming as claimed in claim 1, wherein each selection set of symbols represents symbols positioned on a plurality of spinnable reels, and the display positions represent visible reel positions after a spin of the reels.
 4. A method of gaming as claimed in claim 1 wherein the first and second special symbols are wild symbols.
 5. A method of gaming as claimed in claim 1 wherein the first number of first special symbols is one and the second number of second special symbols is two.
 6. A method of gaming as claimed in claim 3 wherein the first special symbols are positioned to correspond to one reel and shift between reels in subsequent game rounds in the series.
 7. A method of gaming as claimed in claim 6 wherein the first special symbols shift in one direction by one reel position after each game round and the designated number of first game rounds is equal to the number of reels.
 8. A method of gaming as claimed in claim 1 further comprising conducting at least one third game round by controlling a display to display a third number of special symbols at a corresponding third number of display positions of a set of display positions, selecting symbols for the remaining display positions from a third selection set of symbols, and determining a game round outcome from the displayed symbols.
 9. A method of gaming as claimed in claim 8, wherein the third number is greater than the second number.
 10. A method as claimed in claim 1, comprising initiating the series of game rounds as a series of free game rounds in response to a trigger event occurring in a base game round during which symbols are selected from the same selection symbol set but outcomes are determined in a different manner.
 11. A game controller for a gaming system, the game controller arranged to: conduct a series of game rounds in response to determining that the series should commence, at least one first game round of the series of game rounds being conducted by controlling a display to display a first number of special symbols at a corresponding first number of display positions of a set of display positions, selecting symbols for the remaining display positions from a first selection set of symbols, and determining a game round outcome from the displayed symbols, and at least one second game round of the series of game rounds being conducted by controlling a display to display a second number of special symbols at a corresponding second number of display positions of a set of display positions where the second number is greater than the first number, selecting symbols for the remaining display positions from a second selection set of symbols, and determining a game round outcome from the displayed symbols.
 12. A game controller as claimed in claim 11, comprising a symbol selector for selecting symbols for display in the display positions.
 13. A game controller as claimed in claim 11, comprising a special symbol controller for controlling the number and display positions of the special symbols.
 14. A game controller as claimed in claim 13, wherein the special symbol controller is arranged to determine the display position at least partially on a random basis.
 15. A game controller as claimed in claim 11 comprising an outcome determiner for determining each game round outcome.
 16. A game controller as claimed in claim 11 comprising a feature game initiator arranged to initiate the series of game rounds as a series of free game rounds in response to a trigger event occurring in a base game round.
 17. A game controller as claimed in claim 11, implemented, at least in part, by a processor executing code stored in a memory.
 18. A game controller as claimed in claim 11, wherein the game controller controls commencement of the at least one second game round to occur after a designated number of first game rounds.
 19. A game controller as claimed in claim 11, wherein each selection set of symbols represents symbols positioned on a plurality of spinnable reels, and the display positions represent visible reel positions after a spin of the reels.
 20. A game controller as claimed in claim 11, wherein the first and second special symbols are wild symbols.
 21. A game controller as claimed in claim 11, wherein the first number of first special symbols is one and the second number of second special symbols is two.
 22. A game controller as claimed in claim 19, wherein the first special symbols are positioned to correspond to one reel and shift between reels in subsequent game rounds in the series.
 23. A game controller as claimed in claim 22 wherein the first special symbols shift in one direction by one reel position after each game round and the designated number of first game rounds is equal to the number of reels.
 24. A game controller as claimed in claim 11 further arranged to conducting at least one third game round by controlling a display to display a third number of special symbols at a corresponding third number of display positions of a set of display positions, selecting symbols for the remaining display positions from a third selection set of symbols, and determining a game round outcome from the displayed symbols.
 25. A game controller as claimed in claim 24, wherein the third number is greater than the second number.
 26. A gaming system comprising a display for symbols to be displayed at a set of display positions to a player; and a game controller arranged to: conduct a series of game rounds in response to determining that the series should commence, at least one first game round of the series of game rounds being conducted by controlling the display to display a first number of special symbols at a corresponding first number of display positions of a set of display positions, selecting symbols for the remaining display positions from a first selection set of symbols, and determining a game round outcome from the displayed symbols, and at least one second game round of the series of game rounds being conducted by controlling the display to display a second number of special symbols at a corresponding second number of display positions of a set of display positions where the second number is greater than the first number, selecting symbols for the remaining display positions from a second selection set of symbols, and determining a game round outcome from the displayed symbols.
 27. A gaming system as claimed in claim 26, wherein the display forms part of a player interface further comprising a game play mechanism operable by the player to play the game.
 28. A gaming system as claimed in claim 26, wherein the game controller comprises a symbol selector for selecting symbols for display in the display positions.
 29. A gaming system as claimed in claim 26, wherein the game controller comprises a special symbol controller for controlling the number and display positions of the special symbols.
 30. A game controller as claimed in claim 29, wherein the special symbol controller is arranged to determine the display position at least partially on a random basis.
 31. A gaming system as claimed in claim 26, wherein the game controller comprises an outcome determiner for determining each game round outcome.
 32. A gaming system as claimed in claim 26, wherein the game controller comprises a feature game initiator arranged to initiate the series of game rounds as a series of free game rounds in response to a trigger event occurring in a base game round.
 33. A gaming system as claimed in claim 26, wherein the game controller is implemented, at least in part, by a processor executing code stored in a memory.
 34. A gaming system as claimed in claim 26, wherein the game controller controls commencement of the at least one second game round to occur after a designated number of first game rounds.
 35. A gaming system as claimed in claim 26, wherein each selection set of symbols represents symbols positioned on a plurality of spinnable reels, and the display positions represent visible reel positions after a spin of the reels.
 36. A gaming system as claimed in claim 26, wherein the first and second special symbols are wild symbols.
 37. A gaming system as claimed in claim 26, wherein the first number of first special symbols is one and the second number of second special symbols is two.
 38. A gaming system as claimed in claim 37, wherein the first special symbols are positioned to correspond to one reel and shift between reels in subsequent game rounds in the series.
 39. A gaming system as claimed in claim 38 wherein the first special symbols shift in one direction by one reel position after each game round and the designated number of first game rounds is equal to the number of reels.
 40. A gaming system as claimed in claim 26, wherein the game controller is further arranged to conducting at least one third game round by controlling a display to display a third number of special symbols at a corresponding third number of display positions of a set of display positions, selecting symbols for the remaining display positions from a third selection set of symbols, and determining a game round outcome from the displayed symbols.
 41. A gaming system as claimed in claim 40, wherein the third number is greater than the second number.
 42. A gaming system comprising: means for conducting a series of game rounds in response to determining that the series should commence, means for controlling a display to display a first number of special symbols at a corresponding first number of display positions of a set of display positions in at least one first game round of the series of game rounds, means for selecting symbols for the remaining display positions from a first selection set of symbols, and means for determining a game round outcome from the displayed symbols, and means for controlling a display to display a second number of special symbols at a corresponding second number of display positions of a set of display positions where the second number is greater than the first number in at least one second game round of the series of game rounds, means for selecting symbols for the remaining display positions from a second selection set of symbols, and means for determining a game round outcome from the displayed symbols.
 43. A gaming machine comprising: a display mounted within a cabinet for symbols to be displayed at a set of display positions to a player, an input device operable by a player to initiate a play of a game, a game controller disposed in the cabinet in data communication with the display and the input device and comprising a processor and a memory storing game program code which when executed in response to the initiation of play, causes the game controller to conduct a series of game rounds in response to determining that the series should commence, at least one first game round of the series of game rounds being conducted by controlling a display to display a first number of special symbols at a corresponding first number of display positions of a set of display positions, selecting symbols for the remaining display positions from a first selection set of symbols, and determining a game round outcome from the displayed symbols, and at least one second game round of the series of game rounds being conducted by controlling a display to display a second number of special symbols at a corresponding second number of display positions of a set of display positions where the second number is greater than the first number, selecting symbols for the remaining display positions from a second selection set of symbols, and determining a game round outcome from the displayed symbols.
 44. An article of manufacture comprising: a computer readable storage medium; and executable program instructions embodied in the computer readable storage medium that when executed by a programmable system cause the system to perform functions that implement a method of gaming, the functions comprising: conducting a series of game rounds in response to determining that the series should commence, at least one first game round of the series of game rounds being conducted by controlling a display to display a first number of special symbols at a corresponding first number of display positions of a set of display positions, selecting symbols for the remaining display positions from a first selection set of symbols, and determining a game round outcome from the displayed symbols, and at least one second game round of the series of game rounds being conducted by controlling a display to display a second number of special symbols at a corresponding second number of display positions of a set of display positions where the second number is greater than the first number, selecting symbols for the remaining display positions from a second selection set of symbols, and determining a game round outcome from the displayed symbols. 